SBASB22 December   2025 ADS9324

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Timing Requirements
    7. 5.7 Switching Characteristics
    8. 5.8 Timing Diagrams
  7. 6 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Analog Inputs
      2. 7.3.2  Input Clamp Protection Circuit
      3. 7.3.3  Analog Input Impedance
      4. 7.3.4  Programmable Gain Amplifier (PGA)
      5. 7.3.5  ADC Transfer Function
      6. 7.3.6  Reference
      7. 7.3.7  Open Wire Safe Mode
      8. 7.3.8  System Offset Calibration
      9. 7.3.9  System Gain Calibration
      10. 7.3.10 ADC Gain and Offset Error Calibration
      11. 7.3.11 Digital Filter
        1. 7.3.11.1 System Phase Calibration
        2. 7.3.11.2 Block Average Filter
        3. 7.3.11.3 Moving Average Filter
        4. 7.3.11.4 Low-Pass FIR Filter
      12. 7.3.12 Digital Window Comparator
      13. 7.3.13 Alarm Modes
      14. 7.3.14 Data Interface
        1. 7.3.14.1 ADC Channel Modes
        2. 7.3.14.2 Daisy Chain
        3. 7.3.14.3 Diagnostic Flags
        4. 7.3.14.4 ADC Output Data Randomizer
        5. 7.3.14.5 Test Patterns for Data Interface
        6. 7.3.14.6 Digital Output Drive Strength Control
        7. 7.3.14.7 Digital Output Delay Adjustment
    4. 7.4 Device Functional Modes
      1. 7.4.1 Reset
      2. 7.4.2 Normal Operation
      3. 7.4.3 Standby Mode
    5. 7.5 Programming
      1. 7.5.1 Register Write Operation
      2. 7.5.2 Register Read Operation
      3. 7.5.3 Initialization Example - Single Lane Mode on SDOUT
  9. 8 Register Maps
    1. 8.1 ADS93xx Common Registers
    2. 8.2 AIN1 - AIN8 Channel Registers
    3. 8.3 AIN9 - AIN16 Channel Registers
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 16-Channel, Data Acquisition System (DAQ) for Power Automation
        1. 9.2.1.1 Application Curve
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
        1. 9.4.1.1 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information
    1. 12.1 Mechanical Data

7.3.7 Open Wire Safe Mode

The ADS9324 is designed to handle open circuit inputs without producing erroneous conversion results. When both inputs AINnP and AINnM are left in an open circuit condition, the ADC output code remains within ±16 LSB of the 0V reference code. In single-ended conditions, where AINnM is connected to ground, a pull-down resistor (RPD) is needed to keep the ADC output close to zero code, shown in the Figure 7-7. There are three input modes in the devices: differential, single-ended, and single-ended open-wire safe. Open-wire safe mode produces the least change in the ADC output for a given pull-down resistor when the input signal source is floating, see the Table 7-4. To configure the analog inputs in the open-wire safe mode, set the CM_RANGE_AINn to 110b.

ADS9324 Open-Wire Safe Mode Figure 7-7 Open-Wire Safe Mode
Table 7-4 RPD and Offset Increment (RANGE = ±10V, ±5V)
RPD
(kΩ)		 ΔCODE
OPEN-WIRE SAFE		 ΔCODE
SINGLE-ENDED
2.5 2 LSB16 15 LSB16
5 4 LSB16 30 LSB16
7.5 6 LSB16 45 LSB16
10 8 LSB16 60 LSB16
Open (Hi-Z) ~0.18V (RANGE = ±5V)
~0.36V (RANGE = ±5V)		 ~ 1.89V (RANGE = ±5V)
~ 2.10V (RANGE = ±10V)

Figure 7-9 and Figure 7-8 show the ADC output with changes in the pull down resistor value.

ADS9324 Open Circuit ADC Code Error with RPD(Open Wire Safe Mode)Figure 7-8 Open Circuit ADC Code Error with RPD(Open Wire Safe Mode)
ADS9324 Open Circuit ADC Code Error with RPD(Single-ended and Differential)Figure 7-9 Open Circuit ADC Code Error with RPD(Single-ended and Differential)